Next we see fruit in the garden, when God told Adam and Eve not to eat of the tree of the knowledge of good and evil (Gn 2:16-17). We know that they disobeyed God in eating this fruit and it is through this disobedience of the heart that all fell into sin (Gn 3:6). It is in the fall then that bearing fruit from the ground would become difficult and it is through the fall that bearing children would be accompanied with a whole variety of pain. In fact in addition to cursing Satan, God directly cursed the ground saying, “cursed is the ground because of you; through painful toil you will eat of it all the days of your life (Gn 3:17).” Despite this curse of the ground there is grace. Again and again in the Old Testament we see that God takes pleasure in His mandate for the creation to be fruitful and multiply by opening wombs and enabling women to have children. We see that God also owned the first fruits of the field, livestock and of children. One of the reasons that the promised land of Canaan was so desirable was because of the evident fruitfulness of it.
Capitalizing on the understanding of fruitfulness in the Old Testament, Psalm 1 applies the image of fruit to the life of a believer. David wrote:
This became an image that Jeremiah used to describe virtues of a wicked man and the man who has no other security in life but the Lord (Jer 17:5-8). This idea of fruitfulness manifesting in a person’s character is further developed in the wisdom books and the books of the prophets. Jesus picks up on this imagery as well, saying, “bear fruit in keeping with repentance (Matt 3:8),” also “Every tree that does not bear good fruit is cut down and thrown into the fire (Matt 7:15-20),” and “make the tree good and its fruit good, or make the tree bad and its fruit bad, for a tree is known by its fruit (Matt 12:33),” and there are many more examples of this.
The good news of the gospel is that even though we were trees planted in the soil of of this world bearing the rotten fruit of boasting in what we have and do, we can be grafted into the living vine of Jesus Christ. Believers have been given a new life of peace with God. Through being nourished from the water of life, and being grafted to the living vine of Christ by God's gift to us of repentance and faith we also see that we are given the Holy Spirit. As God sanctifies us progressively over time our lives will bear the fruit of the Spirit if we are believers. But this is a fruit that we have to fight for as well (there's a balance of God's sovereignty and our responsibility here). This is what Paul was getting at when he wrote that we should work out our salvation with fear and trembling, for it is God who works in us both to will and work for His good pleasure (Phil 2:12-13). This is what James was getting at when he wrote that faith without works is dead (Jas 2:18-26). Likewise, this is what Peter was getting at when he wrote that we should make our calling and election sure (1 Pet 1:10). Paul's exhortation is still relevant that we "keep in step with the truth of the gospel (Gal 2:14)" and that we, "keep in step [or walk] with the Spirit (Gal 5:25)."